The present invention relates to a coupling assembly used to connect a rotatable motor shaft to a drive shaft, as for example may be used with a fluid pump, and more particularly a coupling assembly which incorporates a jack ring for moving the drive shaft axially relative to the motor shaft to enable adjustment in its final positioning.
Coupling assemblies used to connect a drive shaft in an axially aligned orientation with the end of a rotating motor shaft, so as to be journalled in rotation therewith, are well known. Conventional coupling assemblies typically consist of a two-part sleeve which, in assembly, define a centrally extending bore into which end portions of the motor shaft and drive shaft are located. Screws, pins or other retaining configurations are used to physically couple each of the motor shaft and drive shaft to the sleeve, to thereby mechanically connect the drive shaft to the motor shaft to each other.
With fluid pumps and particularly vertical in-line pumps, the drive shaft typically consists of a pump or impeller shaft to which is connected to a fluid impeller. The impeller is in turn rotatable within a fluid housing to pump the fluid therethrough. It is often desirable to allow for final adjustment of the positioning of the pump shaft axially relative to the motor shaft. In particular, prior to final assembly of vertical in-line pumps, the pump shaft and impeller typically are provided in an initial position resting directly against the bottom of the pump housing. As such, to avoid friction and wear on the pump housing, when connecting the pump shaft to the motor shaft it is desirable to raise the impeller or pump shaft vertically upward, so as to provide a desired degree of clearance between the impeller, the bottom end of the pump shaft and the bottom of the housing.
Heretofore, it has been necessary to manually raise and hold the pump shaft in a position raised relative to the pump housing while the coupling sleeve is secured about both the upper end of the pump shaft and the bottom of the motor shaft. In addition to necessitating extra labour, the inability to manually suspend the pump shaft to a precisely predetermined height during the placement of the coupling sleeve often results in the impeller shaft being positioned either too close or too far from the bottom of the pump housing.
While various individuals have proposed lifting devices to facilitate both the coupling of a motor shaft and a pump or impeller shaft while permitting the impeller shaft to be raised relative thereto, heretofore the prior art lifting devices have achieved limited success as a result of their complex construction and difficulty of use.
Accordingly, the present invention seeks to provide a simplified construction for a coupling assembly used in connecting a motor shaft and a drive shaft in axial alignment, and which enables simplified adjustment in the final positioning of the drive shaft in the axial direction.
Another object of the invention is to provide a coupling assembly for connecting in axial alignment the ends of a motor shaft and a pump shaft of a vertical in-line pump, and which includes a jack ring for use in raising the pump shaft relative thereto which may be easily and inexpensively manufactured.
Another object of the invention is to provide a coupling assembly used in securing the end of a drive shaft in axial alignment with a motor shaft so as to be rotatable therewith, and which includes a jack or lifting ring formed having two substantially identical ring halves which is adapted to be secured to one of the motor or drive shafts.
Another object of the invention is to provide a simplified method of connecting a drive shaft to a motor shaft using a coupling assembly, and which enables simplified final adjustment in the positioning of the drive shaft axially relative to the motor shaft.
To achieve at least some of the aforementioned objects, the present invention provides for a coupling assembly for use in connecting a drive shaft in axial alignment with a motor shaft, so as to be rotatable therewith. The coupling assembly includes a coupling sleeve or jacket which is configured to engage an end portion of one of the motor shaft and the drive shaft and a jack or lifting ring which is secured to the other. More preferably, the coupling assembly secures the motor shaft and drive shaft in a coupled relationship both aligned with and rotatable about a central axis. Preferably, the coupling sleeve extends in the axial direction from a forward end proximate to the motor to a distal rearward end which is remote therefrom. A central bore extends at least partway into and more preferably through the coupling sleeve. The central bore includes a first end portion which extends into the forward end of the coupling sleeve and has a size which is complementary to that of the end portion of the motor shaft. A second other end portion of the bore extends axially into the rearward end of the sleeve and has a size which is complementary to that of an end portion of the drive shaft.
The sleeve is secured to one of the drive shaft or the motor shaft and the jack or lifting ring is coupled to the other of the drive and motor shafts so as to be movable in assembly to a position adjacent one end of the sleeve. The lifting ring includes an aperture which, by way of non-limiting example, could comprise a bore, slot, or groove which extends in the axial direction. The aperture is sized to receive therein a connector which is insertable axially through the aperture and into engagement with the coupling sleeve, so as to moveably connect the coupling sleeve and lifting ring to each other.
In a simplified construction, an internally threaded bore is spaced radially outwardly from the central bore and extends axially into an adjacent end of the coupling jacket. The connector is insertable axially into the threaded bore in threaded engagement therewith, such that the turning of the connector and its engagement with the internal threads moves the lifting ring and drive shaft along the axis relative to the coupling sleeve.
In a more preferred construction, the connecting assembly is used as part of a water or other fluid pump, and the drive shaft is a pump or impeller shaft which is connected to a fluid impeller which is rotatable within a pump housing. In such a construction, the connecting sleeve is secured to the motor shaft and the jack ring is coupled to the pump shaft with the connecting assembly used to raise both the pump shaft and impeller vertically relative to the pump housing.
The jack or lifting ring may be coupled to the pump shaft in a variety of possible manner, including without restriction by the use of mechanical screws, physical weldments and the like. Most preferably, however, the pump shaft is formed having a reduced diameter slot or groove adjacent to an end portion of the shaft which is insertable into the second end of the central bore of the coupling sleeve, and which is delineated in its axial length by radially extending shoulders. The lifting ring is formed having an internal ring opening with a diameter marginally greater than the radial diameter of the pump shaft at the groove, but less than the diameter of the adjacent portions of the pump shaft. The engagement of the jack ring with the shoulders of the groove thus limits axial sliding of the jack ring relative to the pump shaft securing it thereto. The jack ring may be of a number of possible configurations. Most preferably, the lifting ring is formed having a pair of semi-circular ring segments, each formed with the identical configuration. It is to be appreciated that forming the ring segments with an identical configuration advantageously minimizes manufacturing costs and provides a further simplified construction which facilitates the installation of the coupling assembly.
Like the jack ring, the coupling sleeve may be secured to the motor shaft in a number of possible manner including through the use of mechanical fasteners, weldments and the like. In one preferred construction, a retaining ring or collar having an open interior is slid over the motor shaft. The retaining collar is held in a fixed relationship relative to the motor shaft by a series of screw-type fasteners which are brought into engagement with the motor shaft, securing it thereto in a friction fit. In an alternate construction, the retaining collar may be formed as a split collar and adapted for fitted placement within an annular groove formed in the motor shaft. Such a construction would advantageously permit the retaining collar to be positioned within the annular groove without the use of screws. A radially extending groove is formed about the first end portion of the coupling sleeve and which is open into the central bore. The radial groove has a complementary size to the retaining collar and is located such that the retaining collar is insertable within the groove to prevent axial sliding movement of the coupling jacket relative to the motor shaft.
Although not essential, the pump shaft and/or motor shaft may also include a keyway sized to receive partially therein a longitudinally elongated key. Complementary sized slots are formed in the forward and/or rearward ends of the coupling jacket opening into the central bore so as to enable the location of the key at least partially therein. It is to be appreciated that the positioning of the key within both the slots in the coupling jacket and in the keyways of the motor shaft and/or pump shaft prevents slippage of the coupling jacket relative to the pump shaft and/or motor shaft radially about the axis as the motor is rotated. More preferably, the lifting ring may also include a slot which is sized to receive therein part of a key. The slot is formed in the lifting ring relative to the slot which extends into an adjacent portion of the coupling jacket to facilitate the desired alignment of the ring aperture with the threaded bore formed in the adjacent end of the coupling jacket.
Accordingly, in one aspect the present invention resides in combination a motor having a selectively rotatable axially extending motor shaft, a rotatable drive shaft and a coupling assembly for connecting said drive shaft in an axially aligned orientation to said motor shaft for rotation therewith,
the coupling assembly including,
a coupling jacket extending axially from a forward end proximate to said motor to a rearward end distal therefrom, the jacket defining an axially located central bore, a first end of the central bore extending into the forward end of the coupling jacket and being sized to at least partially receive therein an endmost portion of the motor shaft, the second other end of the central bore extending into the rearward end of the coupling jacket and being sized to at least partially receive therein an endmost portion of the drive shaft, an internally threaded bore being spaced radially outwardly from said axis and extending in the axial direction into the rearward end of the jacket,
a lifting ring defining an open interior sized for circumferential placement about the drive shaft and being secured substantially against axially sliding movement relative thereto, the lifting ring including an aperture open in the axial direction, the aperture being located for positioning in substantial axial alignment with the internally threaded bore upon coupling of the lifting ring to the drive shaft, and
a threaded connector having a threaded end with a complementary thread configuration to said internally threaded bore, said connector being insertable axially through said aperture with said threaded end in threaded engagement with said threaded bore, whereby the turning of the threaded connector moves the lifting ring and drive shaft in the axially direction relative to the coupling jacket and motor shaft.
In another aspect, the present invention resides in a coupling assembly for connecting a drive shaft to a selectively rotatable motor shaft for rotation therewith,
the coupling assembly including,
a split coupling sleeve being elongated in an axial direction from a forward end to a rearward end, the sleeve defining an axially located central bore, a first end of the central bore extending into the forward end of the coupling sleeve and being sized to at least partially receive therein an endmost portion of the motor shaft, the second other end of the central bore extending into the rearward end of the coupling sleeve and being sized to at least partially receive therein an endmost portion of the drive shaft,
a lifting ring defining an open interior sized for circumferential placement about the drive shaft and being secured substantially against axially sliding movement relative thereto, the lifting ring including an aperture open in the axial direction, and
a connector being insertable axially through said aperture into engagement with the rearward end of the coupling sleeve, whereby the engagement of the connector with the coupling sleeve moves the lifting ring and drive shaft in the axially direction relative to the coupling jacket and motor shaft.
In a further aspect the present invention resides in a coupling assembly for connecting a pump shaft in a vertically axially aligned orientation with a selectively rotatable motor shaft of a motor for rotation therewith,
the coupling assembly including,
a coupling sleeve extending axially from a forward end proximate to said motor to a rearward end distal therefrom, the sleeve defining an axially located central bore, a first end of the central bore opening into the forward end of the coupling sleeve and being sized to at least partially receive therein an endmost portion of the motor shaft, the second other end of the central bore extending into the rearward end of the coupling sleeve and being sized to at least partially receive therein an endmost portion of the drive shaft, at least one internally threaded bore being spaced radially outwardly from said central bore and extending in the axial direction into the rearward end of the jacket,
a lifting ring defining an open interior sized for circumferential placement about the drive shaft and being secured substantially against axially sliding movement relative thereto, the lifting ring including at least one aperture open in the axial direction, and located for positioning in substantial axial alignment with associated internally threaded bores upon coupling of the lifting ring to the drive shaft, and
at least one threaded connector having a threaded end with a complementary thread configuration to said internally threaded bore, said connectors being insertable axially through a corresponding one of said apertures with said threaded end in threaded engagement with said associated threaded bore, whereby the turning of the threaded connectors moves the lifting ring and drive shaft in the axially direction relative to the coupling jacket and motor shaft.